The present invention relates to II-VI semiconductor devices such as laser diodes and light emitting diodes. More specifically, the present invention relates to a light absorbing layer for a II-VI semiconductor light emitting device.
Buried ridge (buried heterostructure) semiconductor devices are known. Such devices are useful in constructing light emitting or detecting devices, diodes and laser diodes such as those described in U.S. Pat. No. 5,213,998, issued May 25, 1993; U.S. Pat. No. 5,248,631, issued Sep. 28, 1993; U.S. Pat. No. 5,274,269, issued Dec. 28, 1993; U.S. Pat. No. 5,291,507, issued Mar. 1, 1994; U.S. Pat. No. 5,319,219, issued Jun. 7, 1994; U.S. Pat. No. 5,395,791, issued Mar. 7, 1995; U.S. Pat. No. 5,396,103, issued Mar. 7, 1995; U.S. Pat. No. 5,404,027, issued Apr. 4, 1995; U.S. Pat. No. 5,363,395, issued Nov. 8, 1994; U.S. Pat. No. 5,515,393, issued May 7, 1996; U.S. Pat. No. 5,420,446, issued May 30, 1995; U.S. Pat. No. 5,423,943, issued Jun. 13, 1995; U.S. Pat. No. 5,538,918, issued Jul. 23, 1996; and U.S. Pat. No. 5,513,199, issued Apr. 30, 1996.
Historically, laser diodes have generated infrared or red light. However, there are many applications where diodes which emit radiation in shorter wavelengths, for example, in the blue and green portions of the spectrum (i.e., at wavelengths between 590 nm and 430 nm) would be useful. Further, such short wavelength laser diodes would increase the performance and capabilities of many existing systems which currently use infrared and red laser diodes.
There is an on-going effort to improve performance and reliability of II-VI blue-green diodes. One failure mechanism in such devices is the formation of what are known as "dark line defects" (DLD).